As a comparison, we include the Welch's estimate of the cyclic spectral coherence for the analysis of cyclostationary signals
[1]}, [2]}, [3]}.
The result is illustrated in Figure REF .
Note that, the signal length is 6400, the window length is 32, the signal is divided into 14 overlapping blocks and the block overlap is 21 with a Hanning window,
which is suggested in Ref. [1]}.
When observing the coherence, the cyclic frequency of the outer race (approximate 43.3 Hz) and its harmonic components can be identified.
However, the characteristic frequencies of inner race 58.7 Hz and its harmonic components cannot be observed from Figure REF .
This may be caused by the fact that the component of inner race in this case is weak.
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